HP 5061-6565 scsi loopback plug

Sven Schnelle svens at stackframe.org
Mon Jul 9 14:53:49 CDT 2018

On 07/09/2018 08:27 PM, Grant Taylor via cctalk wrote:

> On 07/09/2018 11:58 AM, Al Kossow via cctalk wrote:
>> Someone working on simulating the scsi DIO board in MAME asked me
>> about the scsi loopback test plug. Anyone ever seen one? Is it just
>> wires or are there active parts doing the loopback?
> I've never heard of loopback related to SCSI.  I have seen many
> external terminators that someone may miss-identify as a loopback
> because it seems quite similar to a loopback for serial / parallel.
> Is this by chance what they are talking about

I'm actually the one who asked Al about this test hood. It seems like
it's a SCSI connector that connects the control lines to the data lines.
I've added some code which emulates this in software and the ROM said
'test hood connected' after the HP98265A message, and waited 1 minute on
boot. The 300 Test software also passed all checks. I'll verify that on
real hardware, and post the connections.


More information about the cctech mailing list